Mechanized multi-instrument surgical system

This application is a continuation of U.S. Ser. No. 13/759,036, filed Feb. 4, 2013, which claims priority to U.S. Provisional Application No. 61/594,362, filed Feb. 2, 2012, and U.S. Provisional Application No. 61/714,737, filed Oct. 16, 2012. Each of the foregoing is incorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of access devices and ports through which flexible medical instruments may be introduced into a body cavity and steered or deflected.

BACKGROUND

In conventional laparoscopic procedures, multiple small incisions are formed through the skin, underlying muscle and peritoneal tissue to provide access to the peritoneal cavity for the various medical instruments and scopes needed to complete the procedure. The peritoneal cavity is typically inflated using insufflation gas to expand the cavity, thus improving visualization and working space. In a typical laparoscopic medical procedure, four ports are strategically placed around the abdominal area allowing the surgeon visualization and use of instruments using principles of triangulation to approach the surgical target. While this procedure is very effective and has stood as the gold standard for minimally invasive surgery, it suffers from a number of drawbacks. One such drawback is the need for multiple incisions to place the four ports, which increases the risk of complications such as post-operative herniation and prolonged patient recovery. The four port method also raises concerns of cosmesis, leaving the patient with four abdominal scars.

Further developments have led to systems allowing procedures to be performed using multiple instruments passed through a single incision or port. In some such single port procedures, visualization and triangulation are compromised due to linear instrumentation manipulation, and spatial confinement resulting in what has been known as “sword fighting” between instruments.

Improvements on the prior single port techniques are found in the multi-instrument access devices suitable for use in SPS procedures and other laparoscopic procedures and described in co-pending U.S. application Ser. No. 11/804,063 ('063 application) filed May 17, 2007 and entitled SYSTEM AND METHOD FOR MULTI-INSTRUMENT SURGICAL ACCESS USING A SINGLE ACCESS PORT, U.S. application Ser. No. 12/209,408 filed Sep. 12, 2008 and entitled MULTI-INSTRUMENT ACCESS DEVICES AND SYSTEMS, U.S. application Ser. No. 12/511,043, filed Jul. 28, 2009, entitled MULTI-INSTRUMENT ACCESS DEVICES AND SYSTEMS, and U.S. application Ser. No. 12/649,307, filed Dec. 29, 2009, (US Publication 2011/0230723) entitled ACTIVE INSTRUMENT PORT SYSTEM FOR MINIMALLY-INVASIVE SURGICAL PROCEDURES, each of which is incorporated herein by reference.

U.S. application Ser. No. 12/649,307 (US Publication 2011/0230723) filed Dec. 29, 2009 and entitled ACTIVE INSTRUMENT PORT FOR MINIMALLY-INVASIVE SURGICAL PROCEDURES describes a system for use in performing multi-tool minimally invasive medical procedures using a plurality of instruments passed through a single incision in a body cavity. The disclosed system includes an insertion tube and a pair of instrument delivery tubes (IDTs) extending from the distal end of the insertion tube. Each IDT has steerable distal portion positioned distal to the distal end of the insertion tube. In use, flexible instruments passed through the IDTs are steered by actively deflecting the deflectable distal portions of the IDTs. In particular, proximal actuators (shown as ball-and-socket or gimbal type actuators) for the IDTs are positioned proximally of the insertion tube. Instruments to be deployed from the IDTs into the body cavity are inserted through the proximal actuators into the IDTs. The proximal actuators are moveable in response to manipulation of the handles of instruments extending through the IDTs. Movement of the proximal actuators engages pull elements (e.g. wires, cables etc) that extend from the proximal actuators to the deflectable sections of the IDT's, thus steering the distal portions of the IDTs (and thus the distal ends of the instruments themselves). Additional instruments such as scopes and other instruments may also be passed through the insertion tube (such as through rigid instrument channels) and used simultaneously with the instruments deployed through the IDTs.

Additional examples of proximal actuators and/or IDT shafts that may be used in such access systems are described in U.S. 2011/0184231, entitled DEFLECTABLE INSTRUMENT PORTS, U.S. 2011/0060183, entitled MULTI-INSTRUMENT ACCESS DEVICES AND SYSTEMS, and U.S. 2011/0251599 entitled DEFLECTABLE INSTRUMENT SHAFTS, each of which is incorporated herein by reference.

The present application describes new multi-instrument surgical access systems for use in minimally invasive procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1A</figref> is a perspective view of a motor-assisted multi-instrument surgical system. <figref idref="DRAWINGS">FIGS. 1B through 18</figref> are various views of components of the first embodiment, in which:

<figref idref="DRAWINGS">FIG. 1B</figref> shows the system supported by an arm and positioned relative to an operating table.

<figref idref="DRAWINGS">FIG. 1C</figref> is a partially exploded perspective view of the base unit, roll driver and finger drive assembly.

<figref idref="DRAWINGS">FIG. 1D</figref> is a perspective view of a proximal part of the finger drive assembly.

<figref idref="DRAWINGS">FIG. 2A</figref> is a perspective view of the distal portion of the deployment mechanism.

<figref idref="DRAWINGS">FIG. 2B</figref> is a perspective view of the proximal portion of the deployment mechanism.

<figref idref="DRAWINGS">FIG. 2C</figref> is a plan view of the underside of the proximal portion of the deployment mechanism.

<figref idref="DRAWINGS">FIG. 3</figref> is a perspective view of a finger driver, including the pulley housing.

<figref idref="DRAWINGS">FIG. 4A</figref> is similar to <figref idref="DRAWINGS">FIG. 3</figref>, but without the pulley housing.

<figref idref="DRAWINGS">FIG. 4B</figref> is a bottom perspective view of the components of the finger driver, without the pulley housing, proximal tube and cables.

<figref idref="DRAWINGS">FIG. 5A</figref> shows a pulley of a finger driver.

<figref idref="DRAWINGS">FIGS. 5B and 5C</figref> are partially exploded views of the pulley of <figref idref="DRAWINGS">FIG. 5A</figref>.

<figref idref="DRAWINGS">FIGS. 6A and 6B</figref> schematically illustrate operation of the pulleys of the finger driver.

<figref idref="DRAWINGS">FIG. 7A</figref> is a perspective view showing the underside of the finger drive assembly.

<figref idref="DRAWINGS">FIG. 7B</figref> is a perspective view showing the top side of the base unit.

<figref idref="DRAWINGS">FIG. 8A</figref> is a plan view showing the layout of the motors, sensors and gear assemblies within one half of the base unit.

<figref idref="DRAWINGS">FIG. 8B</figref> is a perspective view of one of the motors and gear assemblies from <figref idref="DRAWINGS">FIG. 8A</figref>.

<figref idref="DRAWINGS">FIG. 9</figref> is a perspective view of a roll driver.

<figref idref="DRAWINGS">FIG. 10</figref> is a perspective view of the roll drive tube and gear assembly of the roll driver.

<figref idref="DRAWINGS">FIG. 11A</figref> is a side elevation view of an instrument that may be used with the system.

<figref idref="DRAWINGS">FIG. 11B</figref> is a perspective view of the handle and proximal shaft of the <figref idref="DRAWINGS">FIG. 11A</figref> instrument.

<figref idref="DRAWINGS">FIG. 12A</figref> is a perspective view of the drive segment of the instrument of <figref idref="DRAWINGS">FIG. 11A</figref>.

<figref idref="DRAWINGS">FIG. 12B</figref> shows the drive segment of <figref idref="DRAWINGS">FIG. 12A</figref> positioned within the roll drive tube.

<figref idref="DRAWINGS">FIGS. 13A and 13B</figref> are end views of an alternative roll drive tube and drive segment, respective.

<figref idref="DRAWINGS">FIG. 13C</figref> shows rotational engagement of the roll drive tube and drive segment of <figref idref="DRAWINGS">FIGS. 13A and 13B</figref>.

<figref idref="DRAWINGS">FIG. 14</figref> shows rotational engagement of a second alternative roll drive tube and drive segment.

<figref idref="DRAWINGS">FIG. 15</figref> is an exploded view of a tubular connector positionable between the housing and roll driver of <figref idref="DRAWINGS">FIG. 1A</figref>.

<figref idref="DRAWINGS">FIG. 16</figref> is a perspective view of the command interface, showing the instrument box separated from the brackets. The handle of an instrument, but not its distal shaft, is shown.

<figref idref="DRAWINGS">FIG. 17A</figref> is a proximal perspective view of the instrument box with the housing removed and with an instrument handle withdrawn from the operative position. The distal shaft of the instrument is not shown.

<figref idref="DRAWINGS">FIG. 17B</figref> is a distal perspective view of the instrument box with the housing removed.

<figref idref="DRAWINGS">FIG. 18A</figref> is a block diagram schematically illustrating components of a variation of the system;

<figref idref="DRAWINGS">FIG. 18B</figref> schematically illustrates an exemplary algorithm for controlling movement of the fingers by the system.

<figref idref="DRAWINGS">FIG. 19</figref> is a perspective view of a second embodiment.

<figref idref="DRAWINGS">FIG. 20</figref> is a perspective view of a third embodiment.

<figref idref="DRAWINGS">FIG. 21</figref> is a perspective view of a fourth embodiment.

<figref idref="DRAWINGS">FIG. 22</figref> is a perspective view of a fifth embodiment.

<figref idref="DRAWINGS">FIG. 23</figref> is a perspective view of a sixth embodiment.

<figref idref="DRAWINGS">FIG. 24</figref> is a perspective view of a seventh embodiment.

<figref idref="DRAWINGS">FIG. 25</figref> is a perspective view of a user interface that may be part of the sixth and seventh embodiments.

<figref idref="DRAWINGS">FIG. 26</figref> is a perspective view of an eighth embodiment.

DETAILED DESCRIPTION

The present application discloses a new motor-assisted multi-instrument surgical system having certain advantages over prior art systems.

Overview

Referring to <figref idref="DRAWINGS">FIG. 1</figref>, a first embodiment of a surgical access system <b>2</b> includes a finger drive assembly <b>200</b> comprising a housing <b>210</b> and an insertion cannula <b>212</b> extending distally from the housing <b>210</b>. Steerable instrument delivery tubes or tubular fingers <b>214</b> extend distally from the insertion cannula <b>212</b>. The tubular fingers <b>214</b> have lumen for receiving passively flexible surgical instruments <b>100</b>. As will be described below, motor-driven finger drivers within the finger drive assembly <b>200</b> steer the fingers <b>214</b> using cables anchored at the distal ends of the fingers. Associated with each tubular finger <b>214</b> is a corresponding motor driven roll driver <b>216</b>—which acts on a distal portion of the instrument shaft to rotate it axially.

In the first embodiment, the motors used to actuate the finger drivers and the roll drivers, as well as associated controllers and electronics are housed within a base unit <b>218</b>, and the finger drive assembly <b>200</b> and the roll drivers <b>216</b> are removably mounted to the base in a manner that delivers motion from the motors to the finger drivers and roll drivers. Spring latches <b>255</b> (<figref idref="DRAWINGS">FIG. 1A</figref>) are positioned to engage the finger drive assembly <b>200</b> and roll drivers <b>216</b> with the base <b>218</b> when they are placed on the base in the proper orientation. Alignment features <b>215</b> (<figref idref="DRAWINGS">FIG. 1C</figref>) on the upper surface of the base unit <b>218</b> mate with or contact corresponding features at the lower surface of the finger drive assembly <b>200</b> and roll drivers <b>216</b>. The alignment features help align the assembled components and to prevent components mounted to the base <b>218</b> from sliding relative to the surface of the base during use.

The base unit <b>218</b> can be a reusable component isolated from the sterile field using a sterile drape or bag (not shown), whereas the finger drive assembly <b>200</b> and roll drivers <b>216</b> may be manufactured as single-use components or re-usable components for a number of times prior to disposal. Re-usable components may be designed for autoclaving or other forms of sterilization.

Command interfaces <b>250</b> are provided for each of the tubular fingers <b>214</b>. The command interfaces <b>250</b> include instrument boxes <b>252</b> that support the instrument handles. The command interfaces <b>250</b> are user input devices that generate signals in response to the user's manipulation of the instrument handle (e.g. pan, tilt and roll) and/or other user inputs. In response to signals generated at the command interface <b>250</b>, the system's motors are controlled to cause the finger driver and roll driver to drive the fingers and instrument in accordance with the user input.

Referring to <figref idref="DRAWINGS">FIG. 1B</figref>, the system <b>2</b> is supported by a support arm <b>204</b> extending from a patient-side cart <b>205</b>, the operating table <b>206</b>, a ceiling mount, or another fixture that positions the arm <b>204</b> where it can support the finger and roll drivers, the associated motors, and the command unit near the operating table, allowing the surgeon to stand patient-side with his/her hands on the instruments <b>100</b>. The arm may be one allowing repositioning of the system <b>2</b> in multiple degrees of freedom. While a robotically-controlled arm could be used with the system <b>2</b>, since control and manipulation of the instruments is achieved using the system <b>2</b> rather than maneuvering of the arm <b>204</b>, the arm may be much simpler in design and smaller in size than those used for conventional robotic surgery. The illustrated arm <b>204</b> is manually positionable about multiple joints and lockable in a selected position. Multiple degree of freedom movement allows the user to position the system <b>2</b> to place the insertion cannula <b>212</b> and the command interfaces <b>250</b> in the desired position relative to the patient and the surgeon. The cart <b>205</b> can be used to carry other equipment intended for use with the system <b>2</b>, such as components supporting visualization, insufflations, stapling, electrosurgery, etc. The arm <b>204</b> has internal springs which counterbalance the weight of system <b>2</b>, allowing it to remain stable in space while the arm is unlocked, and reduces the force required to move the system. While many joint combinations are possible the four bar linkages shown in the pictured embodiment allow for the system <b>2</b>, to pivot about the center of gravity, which reduces the force required to reposition the system.

The system's power supply, computer and user controls (e.g. touch screen computer <b>201</b>), which are discussed with respect to the system schematic at <figref idref="DRAWINGS">FIG. 18</figref>, may be mounted on the cart <b>205</b> with their associated cabling routed through the arm <b>204</b> to the base unit <b>218</b>.

A brief overview of the manner in which the system <b>2</b> is used will facilitate an understanding of the more specific description of the system given below. During use, the fingers <b>214</b> and a portion of the insertion tube <b>212</b> are positioned through an incision into a body cavity. The distal end of a surgical instrument <b>100</b> is manually, removably, inserted through an instrument box <b>252</b> of command interface <b>250</b>, and the corresponding roll driver <b>216</b> and into the corresponding tubular finger <b>214</b> via the finger drive assembly <b>200</b>. The instrument is positioned with its distal tip distal to the distal end of the tubular finger <b>214</b>, in the patient's body cavity, and such that the handle <b>104</b> of the instrument is proximal to the command interface <b>250</b>.

The user manipulates the handle <b>104</b> in an instinctive fashion, and in response the system causes corresponding movement of the instrument's distal end. The motors associated with the finger driver are energized in response to signals generated when the user moves the instrument handles side-to-side and up-down, resulting in motorized steering of the finger and thus the instrument's tip in accordance with the user's manipulation of the instrument handle. Combinations of up-down and side-side motions of an instrument handle will steer the instrument's tip within the body cavity up to 360 degrees. Manual rolling of the instrument handle about the instrument's longitudinal axis (and/or manually spinning of a rotation knob or collar proximal to the instrument handle) results in motorized rolling of distal part of the instrument's shaft <b>102</b> (identified in <figref idref="DRAWINGS">FIG. 11</figref>) using the roll driver <b>216</b>.

Finger Drive Assembly

Referring to <figref idref="DRAWINGS">FIGS. 1A, 1C and 1D</figref>, the insertion tube <b>212</b> of the finger drive assembly <b>200</b> is an elongate tube positionable through an incision in a body cavity. The system is arranged such that multiple instruments may be introduced into the body cavity via the insertion tube. The illustrated embodiment allows for simultaneous use of three or four instruments—two that are actively steered using the tubular fingers <b>214</b>, and one or two that enter the body via passive ports in the finger drive assembly <b>200</b>. Different numbers of active channels (steerable fingers <b>214</b>) and passive ports may instead be used in the system without departing from the scope of the invention. For example, an alternative system might include a single steerable finger <b>214</b> and no passive ports, or the illustrated system might be modified to add one or more steerable fingers <b>214</b> or to add or eliminate passive ports.

Deployment Mechanism

The finger drive assembly <b>200</b> has a deployment mechanism that is operable to simultaneously or independently reposition the distal portion of each finger <b>214</b> to increase or decrease its lateral separation from the longitudinal axis of the insertion cannula <b>212</b>. The deployment mechanism moves the fingers <b>214</b> between an insertion position in which the fingers are generally parallel to one another for streamlined insertion, and one or more deployed positions in which the fingers are pivoted laterally away from the longitudinal axis of the insertion tube as shown in <figref idref="DRAWINGS">FIG. 1A</figref>. U.S. Publication Nos. US 2007-0299387 and US 2011-0230723 illustrate deployment mechanisms that can be used for the system <b>2</b>.

The first embodiment uses a deployment mechanism shown in <figref idref="DRAWINGS">FIG. 2A</figref> using pivotable links <b>12</b> for this purpose, with each link <b>12</b> pivotably coupled between a finger <b>214</b> (only a portion of which is shown in the figure) and one or more elongate members <b>14</b>, which can slide relative to (and, in the illustrated embodiment, partially within) the insertion tube <b>212</b>. Additional links <b>16</b> may extend between the distal end of the insertion tube <b>212</b> and the fingers <b>214</b>, providing additional support for the fingers. In the drawings, these additional links <b>16</b> have a rectangular cross-section with their long edges oriented to resist bending when the fingers are loaded—such as when instruments in the finger are being used to grasp and elevate tissue. The proximal ends of the links <b>16</b> form a hinge coupled to the insertion tube as shown.

As shown in <figref idref="DRAWINGS">FIGS. 2B and 2C</figref> the proximal ends of the members <b>14</b> are connected to a block <b>18</b> moveable relative to the finger drive assembly's housing <b>210</b> between distal and proximal positions to slide the members <b>14</b> between distal and proximal positions. Sliding the members <b>14</b> in this way causes the link arms <b>12</b> to pivot and to thereby move the fingers laterally.

A ratchet feature <b>224</b> (<figref idref="DRAWINGS">FIG. 2B</figref>) is used to retain the longitudinal positioning of the block <b>18</b> relative to the housing <b>210</b> and to thereby maintain the fingers <b>214</b> in a selected deployment position. To deploy, and otherwise alter the lateral spacing of the fingers, the user disengages the ratchet and slides the block <b>18</b> proximally or distally to move the fingers from a first position to a second position. Re-engaging the ratchet causes the ratchet to engage the fingers in the second position. A spring (not shown) biases the ratchet in the engaged position. Other features relating to deployment and ratcheting are disclosed in US Publication No. US 2011-0230723.

The system <b>2</b> may include features that allow it to sense changes in the position of the deployment mechanism as an indicator of the finger's positions relative to the longitudinal axis of the insertion tube <b>212</b>.

As shown in <figref idref="DRAWINGS">FIG. 2B</figref>, pulleys <b>20</b> are rotatably mounted on the housing <b>210</b>. Each pulley <b>20</b> is coupled by a link arm <b>22</b> to the block <b>18</b>, such that longitudinal movement of the block <b>18</b> to deploy the fingers <b>214</b> causes the pulleys <b>20</b> to rotate. At least one of the pulleys <b>20</b> includes a magnet <b>24</b> on its shaft, as shown in <figref idref="DRAWINGS">FIG. 2C</figref>, in which magnets <b>24</b> are shown positioned on the shafts of each pulley <b>20</b>. The magnet <b>24</b> includes diametrically positioned north and south poles and preferably faces downwardly towards the base <b>218</b>.

Encoder chips <b>26</b> (<figref idref="DRAWINGS">FIG. 1C</figref>) on a distal portion of the base <b>218</b> (<figref idref="DRAWINGS">FIG. 2</figref>) are positioned to align with the magnets <b>24</b> when the finger drive assembly <b>200</b> is mounted on the base <b>218</b>. When the deployment mechanism is utilized, each encoder chips <b>26</b> senses the rotational position of the nearby magnet <b>24</b>, which indicates the rotational position of the pulley <b>20</b> and thus the longitudinal position of the block <b>18</b>. This information allows the system to know the state of deployment (i.e. the lateral or x-axis position) of the finger <b>214</b>. Signals generated by the encoder chips <b>26</b> may be used by the system to coordinate proper transformation between a user's input instruction and the corresponding output commands.

In alternative embodiments, each finger may be independently deployed using a separately moveable sliding member <b>14</b>, so as to allow each finger to be laterally repositioned independently of the other finger.

Although the first embodiment uses a manual deployment mechanism, in a modified system, one or more motors may be used to drive the deployment mechanism. In some such systems, motor-driven deployment might be performed independently of the steering of the fingers. In others, the system might dynamically control both the deployment mechanism and the finger drivers as a means to move the fingers into target positions and orientations based on the user's positioning of the instrument handles at the command unit <b>250</b>. Control of the deployment mechanism and the finger drivers at a given point in time can be based on the calculated current position and orientation of the fingers using signals from the encoder chips <b>26</b> together with other sensed information described below.

Instrument Pathways

Referring to <figref idref="DRAWINGS">FIG. 1D</figref>, the finger assembly's housing <b>210</b> has a generally u- or v-shaped configuration, which each “leg” of the u- or v-shaped housing the finger drivers associated with a different one of the steerable fingers <b>214</b>. While not a requirement, this shape leaves working space between the “legs” for additional instruments, as is discussed below.

Ports <b>222</b> for the instruments <b>100</b> are positioned at the proximal end of each leg of the u- or v-shaped housing. These ports <b>222</b> may have seals disposed within the housing <b>210</b> to prevent loss of insufflation pressure through the ports <b>222</b> when no instruments are present in the ports and/or to seal around the shafts of instruments disposed in the ports. Additionally detachable seals may be placed proximal to the ports <b>222</b>. One example of this configuration of seals is illustrated in <figref idref="DRAWINGS">FIG. 15</figref>.

Each port <b>222</b> defines the entrance to an instrument path through the housing <b>210</b> and insertion tube <b>212</b> into a corresponding one of the steerable fingers <b>214</b>. The instrument path includes a tube or series of tubes extending from the port <b>222</b>, through housing <b>210</b> and insertion tube <b>212</b>, and out the distal end of the insertion tube <b>212</b> to form the finger <b>214</b>. The instrument path <b>221</b> has a proximal tube <b>221</b><i>a </i>that extends distally from the port <b>222</b>, and a distal tube <b>221</b><i>b </i>whose proximal end is positioned over the proximal tube <b>221</b><i>a </i>and whose distal end extends through the housing <b>210</b> and insertion tube <b>212</b>. Central lumen in the proximal and distal tubes <b>221</b><i>a</i>, <b>221</b><i>b </i>are continuous to form the instrument path <b>221</b>. The actuation elements or cables <b>223</b> used to steer the finger <b>214</b> extend through lumen in the distal tube <b>221</b><i>b </i>as shown.

Passive ports <b>220</b> (two are shown) are positioned to allow passage of additional instruments through the housing <b>210</b> and the insertion tube <b>212</b>. In the drawings, these additional ports <b>220</b> are shown positioned in the crotch of the u- or v-shaped housing <b>210</b>. These ports allow instruments such as scopes, rigid instruments and other instruments to be passed through the insertion tube and used simultaneously with the instruments deployed through the steerable fingers <b>214</b>. Seals (not shown) in these ports <b>220</b> are positioned to prevent loss of insufflation pressure through the ports when no instruments are present in the ports, and also to seal around the shafts of instruments disposed in the ports <b>220</b>.

Finger

Referring again to <figref idref="DRAWINGS">FIG. 1</figref>, each finger <b>214</b> includes a deflectable distal portion <b>216</b>, which may be formed of a plurality of vertebrae or links as shown, or flexible tubing, slotted or laser-cut metal tubing, or other materials capable of being steered without kinking or buckling. Examples of steerable channels that may be suitable for use as steerable finger <b>214</b> are shown and described in US 2011/0251599 and the other applications referenced herein. A flexible sleeve/liner (not shown) covers the deflectable distal portion <b>216</b> to avoid capture of tissue in gaps between vertebrae or slots.

The distal end of each the finger <b>214</b> may be equipped with a telescoping reinforcement feature positioned on its distal end such that as an instrument tip exits the distal end of the finger, the reinforcement expands distally in a longitudinal direction—surrounding the portion of the instrument tip that extends beyond the end of the finger <b>214</b>. This feature helps support any portion of the instrument shaft that extends beyond the distal end of the finger <b>214</b>, thus avoiding undesirable flexing of the instrument shaft within the body cavity.

The fingers <b>214</b> are steered through selective pulling and/or pushing of the actuation elements <b>223</b> (e.g. wires, cables, rods, etc). In this description the term “cable” will be used to represent any such type of actuation element. The cables <b>223</b> are anchored at the distal end portions of the steerable fingers <b>214</b> and extend proximally through the steerable fingers <b>214</b> into the housing <b>210</b>. The number of cables to be used in a steerable finger may vary. For example, each steerable finger may include two or four cables, wherein distal portions of the cables are arranged 180 or 90 degrees apart, respectively, at the distal end of the finger. In other embodiments, three cables may be used for each finger.

In the illustrated embodiment four cables are used. By “four” actuation cables it is meant that there may be four separate cables/wires etc or two cables/wires each of which has a U-turn anchored at the distal end of the finger such that four cable proximal ends are disposed within the housing <b>210</b>. Additional cables that are not used for actuation may be positioned through the fingers and used to provide feedback as to the position of the tips of the corresponding fingers, using methods to those similar to those described below.

Finger Driver

This section describes the finger driver for one of finger <b>214</b> shown in <figref idref="DRAWINGS">FIG. 1A</figref>. It should be understood that the steerable finger shown on the right side is manipulated using a finger driver having similar features.

The proximal end of each cable <b>223</b> extends out of the proximal end of the tube <b>221</b><i>b </i>and is engaged to a pulley <b>232</b><i>a </i>or <b>232</b><i>b</i>. Each pulley <b>232</b><i>a</i>, <b>232</b><i>b </i>includes a spur gear <b>231</b><i>a</i>, <b>231</b><i>b </i>as shown. While the drawings show the axes of rotation of the <b>232</b><i>a</i>, <b>232</b><i>b </i>pulleys to be non-parallel relative to one another, in other embodiments the pulleys may be oriented to have parallel axes of rotation.

A first pair of the pulleys <b>232</b><i>a </i>is engaged to two cables <b>223</b> that are anchored at points separated by 180 degrees at the distal end of the corresponding steerable finger. The components in the finger drivers are arranged so that each steering motor in the base unit drives one such pair of the cables—although in other embodiments each cable has a dedicated steering motor. To allow each steering motor to drive two cables, each finger driver <b>203</b> is arranged with a first gear <b>230</b><i>a </i>disposed between and engaged with the teeth of the gears <b>231</b><i>a </i>on the first pair of pulleys <b>232</b><i>a</i>, such that rotation of the gear <b>230</b><i>a </i>in a first direction (by action of a steering motor as is discussed below) tensions one cable in the pair and reduces tension on the other cable in the pair, thus deflecting the distal end of the corresponding steerable finger in a first direction. Similarly, rotation of the gear <b>230</b><i>a </i>in the opposite direction (by reversing operation of the corresponding steering motor) deflects the distal end of the steerable finger <b>214</b> (not shown) in the opposite direction by tensioning the opposite cable. A second pair of the pulleys <b>232</b><i>b </i>is similarly driven by a second gear <b>230</b><i>b </i>disposed between and engaged with the teeth on the gears of the second pulleys <b>232</b><i>b</i>. The cables associated with the second gear <b>230</b><i>b </i>are also preferably arranged 180 degrees apart at the distal end of the steerable finger (and offset 90 degrees from the cables associated with the first gear <b>230</b><i>a</i>) allowing for 360 degrees of deflection of the steerable finger <b>214</b>.

The pulleys <b>232</b><i>a, b </i>and gears <b>230</b><i>a, b </i>are housed within a sealed pulley box <b>219</b>. The proximal end of the tube <b>221</b><i>b </i>and the full length of the tube <b>221</b><i>a </i>(<figref idref="DRAWINGS">FIG. 4</figref>) are housed within the sealed box <b>219</b>. Each pulley box is mounted within the housing <b>210</b> of the finger drive assembly <b>200</b> and oriented with the port <b>222</b> exposed at the proximal end of the housing <b>210</b> and with the tube <b>221</b><i>b </i>extending into the insertion tube <b>212</b>. Seals surround the port <b>222</b> and tube <b>221</b><i>b </i>to seal the pulley box against passage of moisture and contamination into the space surrounding the gears and pulleys during cleaning.

<figref idref="DRAWINGS">FIGS. 5A-5C</figref> show one embodiment of a pulley <b>232</b><i>a</i>. Each such pulley includes a spool <b>225</b> rotationally fixed to a shaft <b>227</b>. Gear <b>231</b><i>a </i>is positioned on the shaft <b>227</b> and can spin relative to the shaft <b>227</b>. The pulley <b>232</b><i>a </i>is sprung by a coil spring <b>229</b> disposed around the shaft, with one end of the spring <b>229</b> attached to the gear <b>231</b><i>a </i>and the other end attached to the spool <b>225</b>. The spool includes a pair of posts <b>235</b> spaced 180 degrees apart. The gear has a pair of stops <b>237</b> spaced 180 degrees apart and separated by an annular space <b>241</b>. The posts <b>235</b> of the spool <b>225</b> extend into the annular space <b>241</b>.

The cable <b>223</b> is wound on the spool <b>225</b>. Each pair of the cables is tensioned such that when a finger is in a straight orientation as schematically shown in <figref idref="DRAWINGS">FIG. 6A</figref>, each post <b>235</b> is positioned against one of the stops <b>237</b>. When a motor is used to drive the pulleys to bend the finger to the left as shown in <figref idref="DRAWINGS">FIG. 6B</figref>, the gear <b>231</b><i>a </i>of the pulley <b>232</b><i>a </i>on the left spins in a clockwise direction, and as it spins its stops <b>237</b> remain in contact with the posts <b>235</b> of the corresponding spool—thus the gear and spool move as a solid body. Rotation of the spool tensions the cable <b>223</b>L, causing the finger to bend to the left as schematically shown. At the same time, the gear of the pulley <b>232</b><i>a </i>on the right spins in a counter-clockwise direction and the cable <b>223</b>R slackens due to compliant members of the cable transmission and body. As the gear spins, its stops <b>237</b> rotate away from the posts <b>235</b> of the corresponding gear. Because the gear <b>231</b><i>a </i>and spool <b>225</b> are connected by the spring <b>229</b> (<figref idref="DRAWINGS">FIG. 5C</figref>), the spring force eventually acts on the spool to rotate it counter-clockwise, thus taking up extra slack in the cable <b>223</b>R.

Output from sensors associated with the pulleys is used to calculate the position of the tips of the fingers, force on the cable or finger tip by extension, and to provide redundant sensing of the position of the finger tip relative to that sensed by the motor's encoder. The following discussion of the use of the sensors will focus on the situation in which a finger is pulled to the left as in <figref idref="DRAWINGS">FIG. 6B</figref>, but it should be understand that the same principles apply for each direction in which the finger is steered.

In general, the system makes use of the passive cable in each cable pair (a cable pair being a pair of cables tensioned by a common one of the gears <b>230</b><i>a</i>, <b>230</b><i>b</i>) to provide positional feedback corresponding to the position of the tip of the corresponding finger. Referring to <figref idref="DRAWINGS">FIGS. 4B and 5A</figref>, each pulley <b>232</b><i>a</i>, <b>232</b><i>b </i>has disk magnet <b>243</b> having a distally-facing surface having diametrically positioned north and south poles. Encoder chips <b>245</b> in the base unit <b>218</b> (<figref idref="DRAWINGS">FIG. 8A</figref>, discussed below) are positioned to detect the rotational position of each such magnet. When the finger is steered to a bent position, such as the left-ward bend in <figref idref="DRAWINGS">FIG. 6A</figref>, the cable <b>223</b>L tensioned to produce the bend undergoes elastic stretching under load, and also deforms the shaft of the tubular passage <b>221</b> through which the cable extends. Thus the distance that cable <b>223</b>L was withdrawn to cause the bend does not correspond directly to the amount by which cable <b>223</b>R has advanced in response to bending. Since the passive cable <b>223</b>R is not under the high loads being experienced by the active cable, the distance that the passive cable <b>223</b>R advanced (as indicated by the degree of rotation of the magnet <b>243</b> sensed by the encoder chip), reflects the amount by which the finger is bent and can be used by the system to derive a more accurate measurement of the position of the finger in three dimensional space. This system is beneficial in that it eliminates the need for a cable, pulley and sensor arrangement devoted solely position sensing.

Moreover, the difference between the amount by which the active cable <b>223</b>L was withdrawn and the passive cable <b>223</b>R advanced represents the amount of force applied by the active cable <b>223</b>L at the instrument tip. While feedback as to the force at the tip also comes from measuring current on the steering motors, the force at the tip provides a more direct measure of the force.

Feedback from the motor's encoder can be compared with the positional information obtained from the magnet associated with cable <b>223</b>L and used to detect whether there is an error in the system. For example, if the position measured at the motor is significantly different from the position derived from the positions of the magnets <b>243</b>, the system might alert the user to the possibility that the active cable <b>223</b>L is broken and disable the system <b>2</b>.

If the pulley associated with an active cable is determined to have rotated out of its normal range of motion to its extreme relaxed position (e.g. to a position against the stop <b>237</b> opposite to the stop it should be positioned against in order to be driven by the gear), it will indicate an error in the system that might potentially be an error in the system. Feedback indicating that both pulleys in a pulley pair are in a relaxed state, or have both rotated to a position against a stop when one of the cables is tensioned, is indicative of a broken cable. When error conditions are detected the system, the system may disengage the motors and deliver an error message to the user via the computer interface <b>201</b>.

Motion Transfer—Base Unit to Finger Drivers

The finger driver <b>203</b> receives motion from the steering motors <b>236</b><i>a, b </i>in the base unit <b>218</b> through rotational coupling between elements on the finger drive assembly and elements on the base <b>218</b>. On the finger drive assembly <b>200</b>, members such as driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>(<figref idref="DRAWINGS">FIG. 7A</figref>) are exposed on the bottom of the housing <b>210</b>. Each of the driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>is rotationally fixed to and axially aligned with the one of the gears <b>230</b><i>a</i>, <b>230</b><i>b </i>(<figref idref="DRAWINGS">FIGS. 4A and 4B</figref>) within the housing <b>210</b>, such that rotating each driven shaft <b>226</b><i>a</i>, <b>226</b><i>b </i>rotates the corresponding gear <b>230</b><i>a</i>, <b>230</b><i>b</i>, thus steering the steerable finger <b>214</b> as described above. The driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>may extend from or be recessed at the lower surface of the housing <b>210</b>.

As shown in <figref idref="DRAWINGS">FIG. 7B</figref>, second members such as drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>are exposed at the upper surface of the base <b>218</b> and may extend from or be recessed at the upper surface of the base <b>218</b>. Each drive shaft <b>228</b><i>a</i>, <b>228</b><i>b </i>is releasably engageable with a corresponding one of the driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>on the bottom of the housing <b>210</b> (<figref idref="DRAWINGS">FIG. 7A</figref>). Driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>(<figref idref="DRAWINGS">FIG. 7A</figref>) and drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>(<figref idref="DRAWINGS">FIG. 7B</figref>) are designed for mating engagement or any alternative form of engagement that will allow for the transmission of torque from each drive shaft to its corresponding driven shaft. In the arrangement shown in the drawings, driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>are male components that mate with drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>as their female counterparts. The illustrated male components include hex ball heads of spherical hex keys and the female components include hex sockets for receiving the hex heads. In this embodiment the rotational axis of each first member <b>226</b><i>a</i>, <b>226</b><i>b </i>angularly intersects the rotational axis of the corresponding drive shaft <b>228</b><i>a</i>, <b>228</b><i>b</i>. In other embodiments, however each first member might share a common rotational axis with the corresponding drive shaft.

While the driven shafts and drive shafts are shown as hex mating pieces, any alternative engagement features that will likewise allow transmission of torque from the drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>to the driven shafts <b>226</b><i>a</i>, and <b>226</b><i>b </i>can instead be used.

To facilitate engagement between the drive shafts <b>228</b><i>a, b </i>and the driven shafts <b>236</b><i>a,b</i>, the drive shafts <b>228</b><i>a,b </i>are downwardly displaceable into the base unit <b>218</b> when first contacted by the driven shafts <b>226</b><i>a,b</i>. Springs bias the drive shafts <b>228</b><i>a, b </i>in their outermost position, so that they will spring upwardly once mating features of the drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>and driven shafts <b>226</b><i>a</i>, <b>226</b><i>b </i>engage. Sensors may be positioned in the base unit <b>218</b> to sense when each shaft has returned to its fully extended position, allowing the system to know whether any of the drive shafts <b>228</b><i>a </i>has not properly engaged with the corresponding driven shaft <b>226</b><i>a</i>. This sensed information may be used to lock out use of the system until all shafts are properly engaged. It can also be used to initiate minor rotation of the steering motors associated with the shafts <b>228</b><i>a </i>that have not sprung upwardly, to allow the hex head of the shaft <b>228</b><i>a </i>to move to an orientation where it will engage with the hex socket of the corresponding shaft <b>226</b><i>a. </i>

As will be evident from the following section, engaging the driven shafts and drive shafts allows for the transfer of motion from the system's steering motors to the pulleys that manipulate the cables for steering the fingers.

Base Unit

The base unit <b>218</b> houses steering motors <b>236</b><i>a, b </i>and a roll motor <b>238</b>. The illustrated system has a u- or v-shaped configuration similar to that of the housing <b>210</b>. The base unit <b>218</b> is organized such that motors associated with steering the left-side finger <b>214</b> and with axially rolling an instrument extending through the left-side finger <b>214</b> are in the left side of the base unit <b>218</b> (e.g. in the left leg of the v- or u-shaped housing), and such motors associated with the right-side finger and its instrument are in the right side of the base unit. The computer controllers, motor drivers, and associated electronics for each side of the system are also housed within the base unit <b>218</b>. In this embodiment, two computer controllers/real time processors are included in the base unit <b>210</b>, each associated with one of the fingers, although in other embodiments a single real time processor may be associated with both fingers. Communication between these computers and the user interface computer (e.g. touch screen computer <b>201</b> of <figref idref="DRAWINGS">FIG. 1A</figref>) may use an ethernet TCP/IP connection through a router, or other means. In other embodiments, a touchscreen processor and real time processor are housed within a single computer, eliminating the need for the router.

<figref idref="DRAWINGS">FIG. 8A</figref> shows an arrangement of the motors <b>236</b><i>a, b</i>, <b>238</b> and their corresponding gear assemblies within the base unit's housing (not shown). Each steering motor <b>236</b><i>a, b </i>housed within the base <b>218</b> drives the gears of its corresponding gear assembly <b>240</b><i>a, b. </i>

A gear in each gear assembly <b>240</b><i>a</i>, <b>240</b><i>b </i>is rotationally fixed to one of the exposed drive shafts <b>228</b><i>a</i>, <b>228</b><i>b </i>so that activation of the motors <b>236</b><i>a,b </i>produces axial rotation of each of the drive shafts <b>228</b><i>a</i>, <b>228</b><i>b</i>. Two such steering motors <b>236</b><i>a, b</i>, are shown for each finger, each with a corresponding gear assembly <b>240</b><i>a, b</i>. Motor <b>236</b><i>a </i>is positioned to drive gear assembly <b>240</b><i>a </i>to produce axial rotation of drive shaft <b>228</b><i>a</i>. Motor <b>236</b><i>b </i>drives gear assembly <b>240</b><i>b </i>to produce axial rotation of drive shaft <b>228</b><i>b. </i>

Referring again to <figref idref="DRAWINGS">FIG. 8A</figref>, the output of roll motor <b>238</b> in the base unit is coupled by way of gear assembly <b>242</b> to a member such as a roll driving shaft <b>244</b>, so as to cause axial rotation of the roll member <b>244</b> when the roll motor <b>238</b> is operated. The roll driving shaft <b>244</b> may be similar in configuration to the drive shafts <b>228</b><i>a</i>, <b>228</b><i>b. </i>

Roll Driver

The roll driver <b>216</b> (<figref idref="DRAWINGS">FIGS. 1A, 1B and 9</figref>) includes a housing <b>217</b>. As shown in <figref idref="DRAWINGS">FIG. 10</figref>, a roll drive tube <b>248</b> is axially rotatable within the roll driver housing <b>217</b> (not shown in <figref idref="DRAWINGS">FIG. 10</figref>). Roll drive tube <b>248</b> includes a lumen for receiving a portion of the shaft of instrument <b>100</b> (<figref idref="DRAWINGS">FIG. 1A</figref>). The exterior of the roll drive tube <b>248</b> forms a worm gear, which engages with a roll gear assembly that includes an adjacent worm gear <b>249</b>. The roll gear assembly includes a member such as driven roll shaft <b>234</b> that is exposed at the lower surface of the housing <b>217</b> (not shown). The driven roll shaft <b>234</b> is axially rotatable relative to the roll driver housing <b>217</b>.

The roll driver <b>216</b> is positionable on the base unit <b>218</b> such that the driven roll shaft <b>234</b> rotationally engages with the roll driving shaft <b>244</b> (<figref idref="DRAWINGS">FIG. 7B</figref>) of the base unit <b>218</b>. This rotational engagement allows transfer of torque from the shaft <b>244</b> to the shaft <b>234</b>—thus allowing rotation of the roll drive tube <b>248</b> (and thus the instrument shaft) through activation of the roll motor <b>238</b>. The shafts <b>234</b>, <b>244</b> may be mating pieces similar to those described for the driven shafts and drive shafts <b>226</b><i>a, b </i>and <b>228</b><i>a, b </i>used for steering.

The roll drive tube <b>248</b> has features designed to rotationally engage with corresponding features on the surgical instrument shaft. This engagement allows axial rotation of the roll drive tube <b>248</b> to produce axial rotation of the distal portion of the instrument shaft. Preferred features are those that create rotational engagement between the instrument shaft and the roll drive tube <b>248</b>, but not sliding or longitudinal engagement. In other words, the features are engaged such that axial rotation of the roll drive tube <b>248</b> axially rotates the instrument shaft, but allow the instrument to be advanced and retracted through the roll drive tube <b>248</b> for “z-axis” movement of the instrument tip. Rotational engagement between the instrument shaft and the roll drive tube <b>248</b> should preferably be maintained throughout the useful range of z-axis movement of the instrument tip (e.g. between a first position in which the instrument tip is at the distal end of the finger to a second position in which the instrument tip is distal to the distal end of the finger by a predetermined distance.)

Engagement features for the instrument <b>100</b> and roll drive tube <b>248</b> include first surface elements on a drive segment <b>260</b> of the shaft <b>102</b> of the instrument <b>100</b> (<figref idref="DRAWINGS">FIG. 11</figref>) and corresponding second surface elements on the inner surface of the roll drive tube <b>248</b> (<figref idref="DRAWINGS">FIG. 10</figref>). Examples of surface elements <b>256</b>, <b>258</b> are shown in <figref idref="DRAWINGS">FIGS. 12A-14</figref>. Referring to <figref idref="DRAWINGS">FIGS. 12A and 12B</figref>, the drive segment <b>260</b> of the instrument shaft <b>102</b> includes first surface elements <b>256</b> in the form of splines or ribs extending radially from the instrument shaft and longitudinally along the shaft. The lumen of the roll drive tube <b>248</b> includes second surface elements <b>258</b> in the form of longitudinally extending ribs (also visible in <figref idref="DRAWINGS">FIG. 12B</figref>). The surface elements <b>256</b>, <b>258</b> are positioned such that when the roll drive tube <b>248</b> is rotated, second surface elements <b>258</b> on the interior lumen of the roll shaft contact and cannot rotationally bypass the surface elements on the instrument shaft. The distal ends of the splines <b>256</b> may be tapered such that they are narrower (in a circumferential direction) at their distal ends than they are further proximally, to facilitate insertion of the splines/ribs between corresponding ones of the ribs while minimizing play between the splines <b>256</b> and adjacent ribs <b>258</b> as the roll shaft rotates the instrument shaft. The longitudinal length of the splines <b>256</b> is selected to maintain rotational engagement between the instrument shaft and the roll shaft throughout the desired z-axis range of motion.

The drive segment <b>260</b> of the instrument shaft may have a larger diameter than proximally- and distally-adjacent sections, as shown in <figref idref="DRAWINGS">FIG. 11</figref>. To facilitate insertion of the drive segment <b>260</b> into the roll drive tube <b>248</b>, the drive segment <b>260</b> includes a chamfered distal edge <b>262</b>.

As another example, shown in <figref idref="DRAWINGS">FIGS. 13A-13C</figref>, the drive segment <b>260</b> has a hexagonal cross-section and the roll drive tube <b>248</b> has longitudinal grooves with v-shaped radial cross-sections as shown. Edges <b>256</b><i>a </i>of the drive segment <b>260</b> formed by corner regions of the hexagonal cross section seat in troughs <b>258</b><i>a </i>so as to permit longitudinal sliding of the instrument through the lumen but prevent rotation of the instrument within the lumen.

In another embodiment shown in <figref idref="DRAWINGS">FIG. 14</figref>, drive segment <b>260</b> includes longitudinally extending grooves <b>256</b><i>b</i>. One or more pins <b>258</b><i>b </i>extend radially inwardly from the luminal wall of the roll drive tube <b>248</b> and into engagement with one of the grooves <b>256</b><i>b. </i>

It should be noted that the instrument <b>100</b> is preferably constructed so that the roll drive tube <b>248</b> will cause rolling of the drive segment <b>260</b> and all portions of the instrument shaft <b>102</b> that are distal to it (including the end effector), without causing axial rolling of the instrument handle <b>104</b>. Thus the handle and shaft are coupled together in a manner that permits the instrument shaft to freely rotate relative to the handle when acted upon by the roll drive tube <b>248</b>. For example, the instrument <b>100</b> might includes a roll joint within, or proximal to, the drive segment.

Tubular Connectors

Openings <b>264</b> and <b>266</b> (<figref idref="DRAWINGS">FIG. 1C</figref>) at the proximal and distal surfaces of the roll driver housing <b>217</b> allow passage of an instrument shaft through the lumen of the roll drive tube <b>248</b>. If, as in the first embodiment, the finger drive assembly and the roll drivers are separate components, any gap between the components is bridged by a tubular connector <b>268</b> mounted between the distal opening <b>266</b> of the roll driver housing <b>217</b> and the proximal port <b>222</b> of the housing <b>210</b> so as to provide a continuous instrument path. The tubular connector <b>268</b> can be removably connected to the roll driver housing <b>217</b> and the housing <b>210</b>, or it might be more permanently connected to one or both of them. There may also be a similar tubular connector between the instrument box <b>252</b> and opening <b>264</b> on the roll driver to guide the instrument shaft into the roll driver.

Referring to <figref idref="DRAWINGS">FIG. 15</figref>, the tubular connector <b>268</b> may include a luer port <b>274</b> for use as a flush port or for directing insufflation gas through the finger drive assembly <b>200</b> and into the body cavity. A valve <b>270</b> such as a cross-slit valve is positioned within the tubular connector <b>268</b> to prevent loss of insufflation pressure through its proximal end, when no instrument is present. A second seal <b>272</b> is positioned to seal against the shaft on an instrument that passes through the tubular connector, thus minimizing loss of pressure around the shafts of an instrument disposed through the connector <b>268</b>. In other embodiments, the luer port <b>274</b>, valve <b>270</b>, and seal <b>272</b> may be disposed in the housing <b>210</b>. A single seal, or other seal configurations may also be utilized to seal with and without an instrument present.

Command Interface

Referring again to <figref idref="DRAWINGS">FIG. 1A</figref>, the base unit includes a command interface <b>250</b> equipped to generate signals corresponding to the position of, and/or a change in the position of, a proximal part of the surgical instrument <b>100</b> when the handle <b>104</b> is manually moved by a user (as well as other signals discussed below). The system generates control signals in response to the signals generated at the command interface. Such control signals are used to drive the motors <b>236</b><i>a, b</i>, <b>238</b> to steer the fingers and roll the instrument's shaft in accordance with the user's manipulation of the instrument handle. Thus, manual movement of the instrument handle by the user results in motor driven steering of the instrument's distal end and motor driven axial roll of the instrument shaft.

In this embodiment, it is the instrument's handle <b>104</b> (<figref idref="DRAWINGS">FIG. 1</figref>) whose movement triggers the signals of the command interface that result in steering of the fingers and rolling of the instruments. In other embodiments, a proximal portion of the instrument shaft, or another component of the instrument can be used. Still other embodiments use a separate user input device to generate the signals inputting the desired position of the instrument, rather than user input devices that respond to the user's movement of the instrument handle itself.

Turning to <figref idref="DRAWINGS">FIG. 16</figref>, the command interface <b>250</b> includes a first portion or bracket <b>276</b><i>a </i>that is anchored to the base <b>218</b> (not shown) and rotatable about an axis A1 (which may be generally normal to the surface of the base). A second portion or bracket <b>276</b><i>b </i>is mounted to the first bracket <b>276</b><i>a </i>and is rotatable about axis A2 (which may be generally parallel to the surface of the base and perpendicular to A1).

The instrument box <b>252</b> is positioned on the second bracket <b>276</b><i>b </i>as shown in <figref idref="DRAWINGS">FIG. 1</figref>. Referring again to <figref idref="DRAWINGS">FIG. 1A</figref>, the instrument box includes a housing <b>253</b><i>a </i>removably attached to the second bracket <b>276</b><i>b</i>, so that the instrument box may be detached after surgery for disposal or sterilization and reuse. A passage <b>275</b> for the surgical instrument <b>100</b> extends through the housing as shown. As shown in <figref idref="DRAWINGS">FIG. 16</figref>, in the first embodiment, an opening <b>253</b><i>b </i>in the housing <b>253</b><i>a </i>is slidable over the proximal portion of the second bracket <b>276</b><i>b</i>. A spring latch <b>255</b> (<figref idref="DRAWINGS">FIG. 1A</figref>) between the instrument box <b>252</b> and bracket <b>276</b><i>b </i>engages the two components once the instrument box <b>252</b> has been advanced to the proper position.

The instrument box <b>252</b> is configured to receive the surgical instrument <b>100</b> and to allow the instrument shaft to slide relative to the instrument box <b>252</b> during z-axis positioning of the instrument. The arrangement of the first and second brackets <b>276</b><i>a</i>, <b>276</b><i>b </i>with the instrument box <b>252</b> (and therefore the instrument <b>100</b>) renders the interface <b>250</b> moveable about the axes A1, A2 when the user moves the instrument handle. Up-down movement of the instrument handle results in pitch movement of bracket <b>276</b><i>b </i>about axis A2, and side-side movement of the instrument handle results of yaw movement of bracket <b>276</b><i>a </i>about axis A1, with combined up-down and side-side movement resulting in combined pitch and yaw motion.

Encoders within the command interface <b>250</b> generate signals in response to movement about the axes A1, A2. In particular, a first encoder is positioned such that it will generate signals corresponding to yaw movement of first bracket <b>276</b><i>a </i>(about axis A1). A second encoder is positioned to generate such signals corresponding to pitch movement of second bracket <b>276</b><i>b </i>(about axis A2). Types of suitable encoders include optical or magnetic incremental rotary encoders that generate signals corresponding to the speed and the incremental amount of angular movement are suitable for this purpose. Signals generated by these encoders are received by electronics housed within the base unit <b>218</b> and used to control and drive the steering motors <b>236</b><i>a, b </i>(<figref idref="DRAWINGS">FIG. 7B</figref>).

The instrument box houses components that cause several types of user input signals to be generated by the system in response to user action, including: (a) signals representing the amount by which the user axially rotates the instrument handle or an associated roll knob; (b) signals indicating proper placement of an instrument <b>100</b> into engagement with the system at the instrument box; (c) signals from a user-operable engage/disengage button that lets a user selectively engage or disengage operation of the command interface <b>250</b> from activation of the motors; and (d) signals generated in response to z-axis movement of the instrument to indicate the z-axis position of the instrument <b>100</b>.

Referring to <figref idref="DRAWINGS">FIG. 17A</figref>, the instrument box <b>252</b> includes an elongate tube <b>278</b> having a knob <b>254</b> on its proximal end. A lubricious inner tube <b>279</b> extends through the elongate tube <b>278</b> and has a proximal block <b>282</b> surrounded by the knob <b>254</b>. The block <b>282</b> supports one or more exposed metallic elements, such as the proximally-facing metallic elements <b>284</b>. A magnetic sensor <b>286</b> is within the block <b>282</b>. An opening in the block <b>282</b> is positioned to receive the shaft of an instrument <b>100</b> so that instrument shaft can pass tube <b>278</b>. A spring loaded pin <b>281</b> extends into the opening in the block <b>282</b>.

In <figref idref="DRAWINGS">FIG. 17A</figref>, the handle of instrument <b>100</b> is shown only partially advanced towards the knob <b>254</b> to allow certain features to be visible. A collar <b>106</b> is located on a proximal portion <b>108</b> of the instrument's shaft. The distal side of the collar <b>106</b> is most easily seen in <figref idref="DRAWINGS">FIG. 11B</figref>. It includes a distal part having a notch <b>109</b>. A magnet <b>110</b> in the collar <b>106</b> faces distally. These features are located such that when a user advances the instrument <b>100</b> through the opening in the block <b>282</b> with the notch <b>109</b> facing the pin <b>281</b>, the notch <b>109</b> captures the pin <b>281</b> to rotationally engage the instrument handle to the block <b>282</b>. The magnet <b>110</b> magnetically adheres to the metallic elements <b>284</b> when brought into proximity to them, thus retaining the instrument in position against the block <b>282</b>.

The sensor <b>286</b>, which may be a Hall sensor, is positioned so that it will generate an instrument presence signal when the magnet <b>110</b> is positioned at the metallic elements <b>284</b>. This signal alerts the system that an instrument is properly positioned at the command interface <b>250</b> and the system is therefore ready to control the steerable fingers and the instrument roll position when the user is ready to do so.

The system may therefore be configured such that the motors used to steer a given finger will not be activated in the absence of an instrument presence signal from the sensor <b>286</b>, unless the user otherwise overrides this feature. This feature prevents inadvertent movement of a finger when there is no instrument extending through it.

A user actuated switch is positioned to generate a signal indicating whether the user wishes to place the system in an “engaged” state. The switch may be located near the users hand for easy access, such as on the instrument box <b>252</b>, the instrument, or elsewhere on the system <b>2</b>. Alternatively, the switch may be a foot pedal or voice activated circuit.

In the first embodiment, the switch is actuated using a button <b>288</b> positioned adjacent to the knob <b>254</b> and supported by a button assembly (not shown). A magnet (not shown) is carried by the button assembly. When the engage button <b>288</b> is pressed, the button assembly moves the magnet into or out of alignment with a Hall sensor, causing the Hall sensor to generate a signal that the button has been pressed. When pressure on the button <b>288</b> is released, a spring (not shown) returns the button to its original position. Feedback is provided to the user when the system is moved in and out of the engaged state. For example, an LED <b>245</b> on the instrument box can turn on, or change color, when that part of the system is engaged and turn off when it is disengaged. An auditory tone might additionally be sounded when the system is moved between the engaged and not-engaged state. An electrical connector <b>99</b> (<figref idref="DRAWINGS">FIG. 17B</figref>) in connected between the instrument box and the bracket <b>276</b><i>b </i>to apply a voltage to the LED.

When the engage button has been pressed, the system moves from a “not engaged” state to an “engaged” state with respect to the instrument on that side of the system. When in the engaged state (assuming instrument presence has been detected as discussed above), the system will activate the motors in response to detected movement at the command interface <b>250</b>. Pressing that same engage button <b>288</b> again will generate another signal used by the system to move the system to a “not engaged” state with respect to the instrument on that side of the system. When the system is in the “not engaged” state, the steering and roll motors will not be activated and the orientation of the fingers <b>214</b> and the roll drive tube <b>248</b> remain fixed. The instrument presence sensor <b>286</b> and the user actuated engage button <b>288</b> are therefore useful safety and convenience features designed to prevent activation of the steering and roll motors <b>236</b><i>a,b</i>, <b>238</b> even in the presence of detected movement at the command interface <b>250</b>. This is beneficial in a variety of circumstances, such as when the user wishes to remove his/her hand from the instrument handle without causing inadvertent movement of the fingers within the body as the command interface <b>250</b> shifts position or is inadvertently bumped. The user might also wish to disengage the system in order to maintain the orientation of a finger <b>214</b> within the body cavity while s/he re-positions the command interface to a more ergonomic position, or while s/he replaces the instrument extending through that finger with another instrument s/he wants to deliver to the same location within the body.

If the user elects to change the position of the button <b>288</b> relative to the instrument handle <b>104</b>, s/he may do so by rotating instrument collar <b>106</b> relative to rotation knob <b>254</b>.

A cord (not shown) extending between the block <b>282</b>, knob <b>254</b> or adjacent structures may be used to carry signals from the instrument presence sensor <b>286</b> and the sensor associated with the user actuated button <b>288</b> to circuitry in the base or command interface <b>250</b>.

Roll Input

The instrument box <b>252</b> gives the user two ways in which to trigger motorized rolling of the instrument's shaft. The first way is to spin the knob <b>254</b>; the second way is to rotate the instrument handle <b>104</b>. In the first embodiment, the rotation knob <b>254</b> is positioned near the instrument handle <b>104</b>, allowing the user to find the knob in a position similar to the position of a rotation knob on a standard hand instrument.

Supports <b>290</b>, <b>292</b> are mounted in fixed positions within the instrument box <b>252</b>. A first gear <b>294</b> is rotationally engaged with the exterior surface of the tube <b>278</b>, and a second gear <b>296</b> is adjacent to and engaged with first gear <b>294</b>. Knob <b>254</b>, tube <b>278</b>, and thus gear <b>294</b> are axially rotatable relative to instrument box <b>252</b>, and their rotation produces corresponding rotation of the second gear <b>296</b>. Rotation of the second gear <b>296</b> produces rotation of a magnet positioned such that rotational position of the magnet is sensed by an encoder in the command interface <b>250</b>. There may be a sterile drape present between the magnet and encoder. Referring to <figref idref="DRAWINGS">FIG. 17B</figref>, the magnet is a disk magnet <b>300</b> supported on a post <b>298</b>. The post <b>298</b> extends distally from the second gear <b>296</b> and rotates when the gear rotates. The magnet <b>300</b> includes a distally-facing surface having diametrically positioned north and south poles.

When the instrument box <b>252</b> is mounted on the bracket <b>276</b><i>b</i>, the post <b>298</b> extends into a corresponding opening <b>302</b> (<figref idref="DRAWINGS">FIG. 16</figref>) in the bracket <b>276</b><i>b</i>. An encoder chip <b>304</b> is positioned within the opening <b>302</b> so as to sense the rotational position of the magnet <b>300</b> on the post <b>298</b> (which indicates the rotational position of the knob <b>254</b>). Signals generated by the encoder chip <b>304</b> are used to generate drive signals for the roll motor in response to rotation of the knob <b>254</b>. Roll input is similarly generated through rolling of the instrument's handle. Because the instrument's collar <b>106</b> is rotationally coupled to the tube <b>278</b> (via block <b>282</b>), rotating the instrument handle rotates the tube <b>278</b>, and results in the generation of a signal at the encoder chip <b>204</b> as described above.

In an alternative embodiment, a rotatable knob on the instrument's handle may be rotatable to generate the roll input signals in a similar manner.

Because there is friction at the instruments roll joint <b>260</b> (<figref idref="DRAWINGS">FIG. 11A</figref>) between the distal portion <b>102</b> of the instrument shaft and the proximal portion <b>108</b> of the instrument shaft, rolling of the distal portion can result in a slight roll of the proximal portion <b>108</b> which can generate roll input by the roll encoder chip <b>204</b>. Referring to <figref idref="DRAWINGS">FIG. 17A</figref>, the instrument box <b>252</b> is designed to apply friction against rotational movement of the gear <b>296</b> using an element positioned between the instrument box <b>252</b> housing (or another fixed support within the instrument box) and the gear <b>296</b> or post <b>298</b>. A friction plate <b>247</b> has a first face in contact with the proximal end of the gear <b>296</b> or post <b>298</b>, and a second face in contact with the interior of the instrument box <b>252</b> (not shown in <figref idref="DRAWINGS">FIG. 17A</figref>). The friction plate <b>247</b> imparts frictional resistance against rotation of the gear <b>296</b>. The amount of friction is selected such that it is more than the friction present between the distal shaft <b>102</b> and the proximal shaft <b>108</b> at the instrument roll joint <b>260</b>. Rotation of the proximal portion of the instrument shaft <b>108</b> resulting from friction at the roll joint <b>260</b> is thereby prevented from becoming input to the roll encoder chip <b>204</b>, thus preventing forward feedback.

Z-Axis Movement

Z-axis movement of the instrument to move the instrument tip proximally or distally within the body cavity is manually performed by pushing/pulling the instrument handle <b>104</b>. The instrument box <b>250</b> is configured so that the knob <b>254</b> and instrument handle <b>104</b> can be used to generate instrument roll input regardless of the z-axis position of the instrument handle relative to the instrument box <b>252</b>. When the instrument's collar <b>106</b> is coupled with the block <b>282</b>, z-axis movement of the instrument (i.e. advancement and retraction of the instrument between distal and proximal positions) causes the knob <b>254</b> and tube <b>278</b> to likewise move along the z-axis—keeping the instrument and the roll input features engaged throughout z-axis travel. A constant force spring <b>320</b> (<figref idref="DRAWINGS">FIG. 17B</figref>) is connected between a collar <b>280</b> on a distal portion of the tube <b>278</b> and the support <b>290</b>. When the instrument is advanced in a distal direction, the tube <b>278</b> pushes the collar <b>280</b> distally, against the force of the spring <b>320</b>. When the user removes the instrument handle <b>104</b> from the instrument box <b>252</b>, the spring <b>320</b> retracts the tube <b>278</b> and thus the collar <b>280</b> returns to the proximal position. When an instrument is present the spring <b>320</b> force would be less than the frictional force required to move the instrument, and the instrument would maintain position with no user input.

The instrument box may include a lock to prevent the tube <b>278</b> from advancing distally during insertion of an instrument into the tube <b>278</b>. The lock may be a mechanical latch manually releasable by the user or electronically released in response to a signal produced by the instrument presence sensor.

The features of the instrument box allowing the z-axis position of the instrument to be determined will next be described with continued reference to <figref idref="DRAWINGS">FIG. 17B</figref>. A pin <b>308</b> extends laterally from the collar <b>280</b>. A lever arm <b>310</b> has a first end having a slot <b>312</b> slidable over the pin <b>308</b>. A second end of the lever arm <b>310</b> is pivotably coupled to a stationary lever arm mount <b>314</b> mounted within the instrument box. A magnet <b>316</b> is positioned at the pivot axis of the lever arm <b>310</b>, and rotates as the lever arm <b>310</b> pivots. The magnet <b>316</b> includes a distally-facing surface having diametrically positioned north and south poles.

Referring to <figref idref="DRAWINGS">FIG. 16</figref>, when the instrument box <b>252</b> is mounted on the bracket <b>276</b><i>b</i>, the magnet <b>316</b> (<figref idref="DRAWINGS">FIG. 17A</figref>) is positioned in alignment with an encoder chip <b>318</b> mounted in the bracket <b>276</b><i>b</i>. The encoder chip <b>318</b> generates signals representing the rotational position of the magnet <b>316</b> and thus lever arm <b>310</b>, from which the axial position of the tube <b>278</b> and thus the instrument <b>100</b> can be derived by the system.

A scaling factor is the amount by movement of the instrument or finger is scaled upwardly or downwardly relative to the user's movement of the instrument handle. The system <b>2</b> uses the determined z-axis position of the instrument to dynamically adjust the scaling factors used in control of the steering motors. For example, smaller scaling factors might be used for steering when the instrument is fully extended from the finger than would be used when the instrument tip is closer to the tip of the finger to give consistent steering relative to the user input regardless of the instrument's z-axis position.

The first and second brackets <b>276</b><i>a, b </i>of the command interface <b>250</b> may be covered by sterile drape for use, while the instrument box <b>252</b> remains external to the drape.

Electromechanical Block Diagram

<figref idref="DRAWINGS">FIG. 18A</figref> shows an electromechanical block diagram of the system <b>2</b>, as slightly modified for an embodiment in which a roll input wheel is positioned on the instrument shaft rather than on the instrument box as discussed above. Certain other features, including the deployment sensor, are not shown, and in the <figref idref="DRAWINGS">FIG. 18A</figref> embodiment the roll driver is included as part of the base unit (labeled “Drive Assembly”) rather than as a separate component.

Use

To use the system <b>2</b>, the base unit <b>218</b> and the first and second portions <b>276</b><i>a</i>, <b>276</b><i>b </i>of the command interface <b>250</b> are covered by a sterile drape. The housing <b>210</b> of the finger drive assembly <b>200</b> and roll driver <b>216</b> are mounted to the base unit to engage the motor driven members <b>228</b><i>a</i>, <b>228</b><i>b</i>, <b>244</b> of the base unit <b>218</b> with the driven members <b>226</b><i>a, b</i>, <b>234</b>. The system monitors engagement between the shafts <b>228</b><i>a</i>, <b>228</b><i>b</i>, <b>244</b> of the base unit with the shafts <b>226</b><i>a,b</i>, <b>234</b> of the finger and roll drivers, and shafts <b>228</b><i>a</i>, <b>228</b><i>b</i>, <b>244</b> found to not have not engaged with their counterparts may be rotated slightly through motor activation as described in “Motion Transfer” section above.

The instrument box <b>252</b> is mounted to the second portion <b>276</b><i>b </i>of the command interface <b>250</b>. Spring latches <b>255</b> engage to secure the housing <b>210</b> and roll driver <b>216</b> to the base unit <b>218</b> when the components are properly aligned. Similar spring latches are engaged to secure the instrument box <b>252</b> to the portion <b>276</b><i>b </i>of the command interface.

Sterile tubular connectors <b>268</b> are coupled between the roll driver <b>216</b> and the port <b>222</b> on the housing <b>210</b>, and similar connectors may be positioned between instrument box <b>252</b> and the roll driver <b>216</b>. Once the system <b>2</b> is assembled, the distal end of the finger drive assembly <b>200</b> is positioned within the body cavity of the patient. Alternately, the finger drive assembly may also be positioned inside the patient and then assembled to system <b>2</b>. For easy insertion into the body cavity, the deployment mechanism is used to position the fingers <b>214</b> in a streamlined side-by-side configuration using the links <b>12</b>. The fingers <b>214</b> and a portion of the insertion tube <b>212</b> are the passed through the incision into the body cavity. The distal tip of a medical instrument (e.g. forceps, graspers or other flexible shaft hand instruments) is inserted through the instrument box <b>252</b> and advanced distally. Advancing the instrument causes the tip to exit the instrument box <b>252</b>, pass through the roll driver <b>216</b>, then into port <b>222</b> on the proximal end of the finger drive assembly's housing <b>210</b>, and through the corresponding finger <b>214</b> until the distal end of the instrument extends from the distal end of the finger <b>214</b>.

When an instrument is fully inserted through the command interface <b>250</b>, instrument presence signals are generated at sensor <b>286</b> (<figref idref="DRAWINGS">FIG. 17A</figref>).

Additional instruments such as scopes, graspers and the like are passed through the insertion cannula via ports <b>220</b> for use simultaneously with the instruments deployed through the fingers.

The deployment mechanism is used to adjust the lateral spacing of each finger (and thus the instrument passed through it) relative to the longitudinal axis of the insertion cannula as described with respect to <figref idref="DRAWINGS">FIGS. 2A through 2C</figref>.

Before the user can steer or roll the instrument using the system, s/he presses the engagement button <b>288</b> to cause the system to enter into the engaged state.

At least when the system is placed in an engaged state, the system senses the positions of the brackets <b>276</b><i>a,b </i>and the roll input magnet <b>300</b> to determine the starting position of the instrument's handle <b>104</b>.

If the system is in an engaged state and the instrument's presence has been detected, the system will respond to steering and roll input at the command interface <b>250</b> by engaging the steering and roll motors to steer the finger and roll the instrument. To steer the instrument <b>100</b> within the body, the user manipulates that instrument's handle <b>104</b>. For example, to move the instrument's end effector upwardly, the user will lower the handle; to move the end to the left, the user will move the handle to the right. (Although in alternate arrangements, the system may be configured such that the end effector moves in the same direction as the handle—so that, for example, raising the handle raises the end effector). The encoders in the command interface <b>250</b> sense the movement or position of the handle by sensing rotation of the brackets <b>276</b><i>a, b </i>relative to axes A1, A2. In response, the system generates control signals to activate motors <b>236</b><i>a, b </i>to thereby steer the finger and the instrument that extends through it. To axially roll the instrument, the user axially rolls the instrument handle <b>104</b> or the rotation knob <b>254</b> relative to the instrument box <b>252</b>, producing signals at the roll encoder chip <b>304</b>. In response the roll motor <b>238</b> is activated to roll the distal part <b>102</b> of the instrument shaft. To position the instrument further into the body cavity, the user pushes the instrument handle <b>104</b> distally. This z-axis movement of the instrument is sensed by encoder <b>318</b>, and the z-axis position of the instrument may be used by the system to dynamically adjust scaling factors for finger steering and/or instrument roll.

<figref idref="DRAWINGS">FIG. 18B</figref> is a schematic of an exemplary drive control sequence for controlling the steering motors to drive the fingers based on sensed information (e.g. approximations of the positions of the fingers, the positions of the user interface etc), using forward and reverse mapping and PID control.

Actuation of the instrument's end effector, such as the opening/closing of jaws, is carried out in conventional fashion using manual actuators (e.g. levers, knobs, triggers, slides, etc.) on the instrument handle. If desired, an instrument may be withdrawn from the system during the procedure, and replaced with a different instrument, which again may be steered and axially rotated through manipulation of the handle as described.

The first embodiment is but one example of ways in which the mechanized system may be configured. Various modifications may be made to that embodiment without departing from the scope of the invention.

A few such modifications will next be described, but many others are possible and within the scope of the invention.

While the drawings show the two finger drivers in the housing <b>210</b> and each roll driver <b>216</b> in a separate housing, other embodiments use different layouts. For example, the design may be modified to position the roll drivers <b>216</b> in a common housing with the finger drivers. As a second example, the roll drivers <b>216</b> might both be mounted in a common housing that is separate from the housing <b>210</b> containing the finger drivers. In another embodiment, the roll driver and finger driver associated with the left-instrument may be a common housing, with a separate housing used for both the roll driver and finger driver associated with the right-instrument. Other embodiments might package each of the roll drivers and finger drivers as four separate components.

In other embodiments, the motors are integrated into the assemblies of the corresponding finger drivers and the roll drivers rather than being detachable from them.

Second Embodiment

The system <b>2</b>A of the second embodiment, shown in <figref idref="DRAWINGS">FIG. 19</figref>, differs from the first embodiment primarily in that the features of the roll driver are incorporated into the base. More particularly, a base <b>218</b><i>a </i>includes an elevated portion <b>216</b><i>a </i>that houses the roll drive tube <b>248</b> (not shown). An instrument passage extends between a proximal opening <b>264</b><i>a </i>and a distal opening (not shown) in the elevated portion <b>216</b><i>a</i>. The instrument shaft extends through the passage elevated portion <b>216</b><i>a </i>between the command interface <b>250</b> and the finger drive assembly <b>200</b>. A sterile tubular insert (not shown) is insertable through the instrument passage in the elevated portion <b>216</b><i>a </i>to prevent the instrument <b>100</b> from contaminating the passage.

Third Embodiment

Referring to <figref idref="DRAWINGS">FIG. 20</figref>, a third embodiment of a surgical access system <b>2</b>B includes a body <b>210</b><i>a </i>and an insertion cannula <b>212</b> extending distally from the body <b>210</b><i>a</i>. Fingers <b>214</b> extend from the insertion cannula <b>212</b>. The finger <b>214</b> may have properties similar to those described elsewhere in this application.

Each finger includes a dedicated deployment mechanism operable to independently reposition the distal portion of the fingers <b>214</b> to increase or decrease its lateral separation from the longitudinal axis of the insertion cannula <b>212</b>. Each deployment mechanism includes a rigid, longitudinally slidable, member <b>14</b><i>a </i>and at least one link arm <b>12</b><i>a </i>(two are shown for each finger). The rigid member <b>14</b><i>a </i>may be constructed of a proximal portion comprising a straight, single-lumen, tube made of stainless steel or rigid polymeric material, and a distal bar extending from the tubular proximal portion. The distal bar may be integral with a portion of the wall of the tubular proximal portion. Each finger <b>214</b> extends distally from the lumen of the tubular proximal portion of the rigid member <b>14</b><i>a. </i>

The deployment system works similarly to that described for the first embodiment. Each link <b>12</b><i>a </i>has a first end pivotally coupled to the rigid member <b>118</b> and a second end pivotally coupled to a corresponding finger <b>214</b>, proximally of its distal end. In the illustrated embodiment, these pivotal connections are formed at collars <b>122</b> disposed on the fingers. The rigid member <b>14</b><i>a </i>is longitudinally moveable relative to the insertion cannula <b>212</b> to pivot the links <b>120</b> inwardly and outwardly. In the illustrated configuration, sliding <b>14</b><i>a </i>in a distal direction pivots the second ends of the links <b>120</b> outwardly to deploy the corresponding finger or to further separate the finger from the longitudinal axis of the insertion cannula <b>212</b>. Alternate configurations may operate in reverse, so that retraction of the member <b>14</b><i>a </i>increases the separation of the fingers.

Each finger may further include a support member or strut <b>124</b> having a first end pivotally connected to the collar <b>122</b> and a second end pivotally connected to the corresponding one of the members <b>14</b><i>a </i>or to the insertion cannula <b>212</b>. The support struts <b>124</b> support the fingers, helping to maintain the longitudinal orientation of the fingers, and preventing them from sagging or buckling during use.

Slide rings <b>126</b> are shown for independently sliding each member <b>14</b><i>a </i>longitudinally for finger deployment, allowing the user to advance/retract the member <b>14</b><i>a </i>by advancing/retracting the ring <b>126</b> relative to the body <b>210</b><i>a</i>. The ring may include a ratchet feature function as described in the '307 application, which releasably locks the finger in a chosen longitudinal and lateral position by releasably engaging the longitudinal position of the member <b>14</b><i>a</i>. <figref idref="DRAWINGS">FIG. 20</figref> shows that this arrangement allows each finger to be deployed to have a different amount of lateral separation and longitudinal extension.

The tips T of instruments <b>100</b> are shown extending from the distal ends of the fingers. The body <b>210</b><i>a </i>includes proximal openings <b>128</b> for receiving the instruments. To deploy an instrument <b>100</b> from a finger <b>214</b>, the tip of that instrument is inserted through one of the proximal openings <b>128</b> and advanced through the body <b>210</b><i>a</i>, insertion cannula <b>212</b> and finger until its tip T or end effector extends out of the finger. In the <figref idref="DRAWINGS">FIG. 20</figref> drawing, the handle <b>104</b> for the instrument used through the finger on the left is not shown, so as to allow the proximal opening <b>128</b> to be seen.

A primary difference between the third and first embodiments is that the features described for inclusion in the first embodiment's finger drivers, roll drivers, command interface (including the instrument box) and base unit are incorporated into the housing <b>210</b><i>a. </i>

Sensors <b>130</b> are positioned on the body <b>210</b><i>a </i>to sense pitch and yaw movement of the instrument handle <b>104</b>. Motors <b>236</b><i>a, b </i>in the body <b>210</b><i>a </i>are engaged with cables that extend through the fingers and that are anchored to the fingers (e.g. at 90 degree intervals) to deflect the fingers according to the sensed position of the handle. For example, a first motor <b>236</b><i>a </i>may be positioned to drive a first pair of cables corresponding to yaw motion of the finger distal end, and a second motor <b>236</b><i>b </i>may be positioned to drive a second pair of cables corresponding to pitch motion of the finger distal end.

Automation may also be provided for driving axial rotation of an instrument disposed through a finger. A handle sensor <b>304</b> is positioned to sense axial rotation of the instrument handle <b>104</b>, and is operatively associated with a roll motor <b>238</b> that will produce or aid an axial roll of the instrument or a finger using gear <b>134</b>.

As with the first embodiment, actuation of the instrument's end effector, such as the opening/closing of jaws, is carried out in conventional fashion using actuators (e.g. levers, knobs, triggers, slides, etc.) on the instrument handle. If desired, an instrument may be withdrawn from the system during the procedure, and replaced with a different instrument, which again may be steered and axially rotated through manipulation of the handle as described.

The system <b>100</b> may include a mount <b>90</b> engageable with a stabilization arm such as the arm <b>204</b> (<figref idref="DRAWINGS">FIG. 1B</figref>) that can be coupled to a cart, the surgical table or to another fixture within the operating room. The stabilization arm may be manually positionable or adjustable using motor driven joints and telescoping members, allowing the height and orientation of the system <b>2</b>B to be adjusted using a user input such as foot pedals or other input devices.

Fourth Embodiment

The <figref idref="DRAWINGS">FIG. 21</figref> embodiment is similar to the <figref idref="DRAWINGS">FIG. 20</figref> embodiment, but further incorporates a mechanism for Z-axis movement of each finger <b>214</b>. While use of the slide ring <b>126</b> in the <figref idref="DRAWINGS">FIG. 20</figref> embodiment produces a z-axis change of the corresponding finger position, the <figref idref="DRAWINGS">FIG. 21</figref> arrangement allows for z-axis movement that is independent of the lateral position of the finger relative to the insertion cannula <b>212</b>.

In particular, the system has two body sections <b>210</b><i>c</i>, each of which is longitudinally slidable along a central track <b>136</b>. Each body section is coupled to one of the fingers and its corresponding deployment system (member <b>14</b><i>a</i>, links <b>12</b><i>a</i>, support strut <b>124</b>, deployment ring <b>126</b>). In one embodiment, the insertion cannula <b>212</b> is coupled to the track <b>136</b>, and each finger and its drive and deployment systems move longitudinally relative to the cannula in response to manual pushing/pulling by the user. While the primary z-axis adjustment is now carried through on a platform with a linear bearing for each side of the system, the deployment mechanism remains for the adjustment of the tool separation (identified as x-axis in the drawings). Note that each side has an independent deployment system so that the span is independently controlled for each instrument.

Fifth Embodiment

The <figref idref="DRAWINGS">FIG. 22</figref> embodiment is similar to the <figref idref="DRAWINGS">FIG. 21</figref> embodiment, but is provided in a more modular format. This embodiment includes independent body sections <b>210</b><i>d </i>which house the pitch, yaw and roll motors <b>236</b><i>a, b</i>, <b>230</b>, the sensors <b>130</b>, <b>304</b>, and which include the opening <b>128</b> for receiving the instrument <b>100</b>. A pair of finger/roll driver <b>203</b><i>a </i>each having pulleys <b>232</b>, cables (not shown), and a roll drive tube <b>248</b> are provided, with each finger/roll driver <b>203</b><i>a </i>connected to one of the fingers <b>214</b>. Each finger/roll driver <b>203</b><i>a </i>is releasably engagable with a body section <b>210</b><i>d </i>in a manner that allows the motors in the body section <b>210</b><i>d </i>module to actuate the pulleys <b>232</b> in finger/roll driver <b>203</b><i>a </i>so as to tension the cables and roll the finger/roll driver <b>203</b><i>a </i>to steer the finger and roll the instrument. Slide rings <b>126</b> for finger separation (x-axis) are located on the finger/roll drivers <b>203</b><i>a. </i>

Sixth Embodiment

In the <figref idref="DRAWINGS">FIG. 20-22</figref> embodiments, pitch, roll and yaw are sensed and the finger is electromechanically controlled to position the instrument, however the jaw clamping action or other end effector action of the instrument is mechanically driven by a mechanical actuator on the instrument handle. The <figref idref="DRAWINGS">FIG. 23</figref> embodiment is largely similar to the <figref idref="DRAWINGS">FIG. 22</figref> embodiment, but rather than using a hand instrument having a mechanical actuator, it uses an alternate surgical instrument <b>100</b><i>a</i>. The instrument <b>100</b><i>a </i>engages with a motor <b>138</b> in the motor module that is activated to operate the end effector (e.g. jaw) of the tool. In one embodiment, control of the finger and roll drivers is responsive to user manipulation of the instrument <b>103</b><i>a </i>to control pitch, roll and yaw as discussed with respect to prior embodiments, but the system is instrument configured to receive signals from an input device (e.g. a switch, foot pedal) to initiate actuation of the end effector via motor <b>138</b>. In other embodiments, the pitch, roll, yaw and jaw motors may be operable in response to signals received from a separate user input device such as a joystick or other forms of input device(s) rather than manual manipulation of the instrument <b>103</b><i>a. </i>

Seventh Embodiment

The <figref idref="DRAWINGS">FIG. 24</figref> embodiment is similar to the <figref idref="DRAWINGS">FIG. 23</figref> embodiment, but it automates the z-axis movement using a motor <b>140</b> that advances/retracts the bodies <b>210</b><i>e </i>and the finger/roll driver <b>203</b><i>a </i>along the track <b>136</b>. Moreover, it eliminates the mechanical deployment mechanism and instead automates the x-axis or lateral positioning of the finger using an additional motor <b>142</b> in each body <b>210</b><i>e</i>. The motor <b>142</b> advances/retracts the element <b>14</b><i>a </i>to expand the links <b>12</b><i>a </i>for deployment and x-axis positioning.

Automating the z- and x-axis movement allows for complex volumetric motions of the instrument beyond what can be achieved using mechanical z- and x-axis movement. Providing a dynamic z-axis increases reach of the instrument while introducing a dynamic x-axis enables complex orientation movements of the instrument tips. Tip movement in the x-direction can in a sense be de-coupled from movement in the z-direction, by automatically adjusting the finger's z-axis position to off-set z-axis changes resulting from pivoting of the links <b>12</b><i>a </i>during x-axis adjustments.

<figref idref="DRAWINGS">FIG. 25</figref> shows but one example of a user input device that can be used in systems such as the <figref idref="DRAWINGS">FIGS. 23 and 24</figref> systems that use input devices that are separate from the instrument handle and shaft. A input device <b>500</b> shown in <figref idref="DRAWINGS">FIG. 25</figref> includes a handle to be manipulated by a user in accordance with the desired position of the surgical instrument. The input device incorporates at least four sensors (associated with multiple pivot joints in a control handle) and an actuator <b>502</b> for simulating the grasping load to be achieved at the instrument's end effector. The input device is connected to the body <b>210</b><i>d</i>, <b>210</b><i>e </i>through digital communication wires and can be located on or near the body <b>210</b><i>d</i>, <b>210</b><i>e </i>at the patient's bedside, preferably within the sterile field. For example, the input device <b>500</b> and the body might be positioned on a common arm (such as arm <b>204</b>), on different arms supported by a common cart or other fixture (e.g. the operating table or a ceiling mount), or on separate arms on the same or different fixtures. The <figref idref="DRAWINGS">FIGS. 23 and 24</figref> systems may be provided with various interchangeable tools <b>100</b><i>a</i>, each having a different end effector, allowing the user to exchange tool modules as needed during the course of a surgical procedure.

Eighth Embodiment

<figref idref="DRAWINGS">FIG. 26</figref> shows a system <b>2</b>E that is similar to the first embodiment. However, the finger drive assembly <b>203</b>, roll drivers <b>216</b>, command interfaces <b>250</b>, motor drivers and associated electronics are integrated into a single component. Two steering motors <b>236</b><i>a, b </i>are shown on each side of the system <b>2</b>E, one for each pair of cables. However, each cable may instead have its own dedicated motor.

While certain embodiments have been described above, it should be understood that these embodiments are presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. This is especially true in light of technology and terms within the relevant art(s) that may be later developed. Moreover, features of the various disclosed embodiments may be combined in various ways to produce various additional embodiments.

Any and all patents, patent applications and printed publications referred to above, including for purposes of priority, are incorporated herein by reference.